Process for the manufacture of milk sugar



2 Sheets-Sheet l A. DE LISLE PROCESS FOR THE MANUFACTUREOF MILK. SUGARFiled Maron 1e. 1937 Jan. 24, 1939.'.

Jan. 24,` 1939.` A. DELlsLE Y' PROCESS.A FOR THE MANUFACTURB,OPMILKlSUGAR LFiled Match 16, 1957 2 sneetsfsheet 2 Patented J an. 24, 119392,145,109- f PRooEss Foa THE MANUFAo'rU'im or MILK suenal y Auguste deLisle, Glendale, Ari'z.', assignor 'to- Associated Dairy ProductsCompany, Glendale, Y Ariz., acm-poration of Arizona y Application March''1f6, 1937, SerialjNo.k1 31,233 .fr claims (ci. 12v-31) v This inventionrelatesto y an improved process of preparing dehydrated food productsand pertains particularly to the `manufacture of milk sugar.4 ,l p

'The present invention has forits primary. object to provide acontinuous process for the production of milksugar in usable form asmilksugar, without 'the necessity of reinelting the .'irst solid productsfor filtration and recrys'talliaation, Vas is. customary in..followngprocesses as at present carried out.

bywhich the `dissolvedsugar is -causedto beV Another object of`theinvention is to provide a new and novel process of dehydrating solidscarrying liquids such as milk, skim milk, whey, buttermilk, and thelike, without the use of .the usual evaporators and by a continuous`procedure whereby the inal product will be ready for immediate use.

A still further object of the invention Vis .toprolvide an improvedprocess of preparing dehydrated products, more particularly milk sugar,whichinvolves the `novel step of` using .waste stack gases or otherinert gases, as the drying mediumfso that the product `produced .by theprocesshas; :a more lasting qualityand superior flavor-than otherdehydrated products in'which the drying gases used contain highpercentages of oxygen; y

A still further object of the invention isflto provide in a novelcontinuous process 'of :the character hereinafter set forth, an improvedform of evaporating or dehydrating chamber and novel means associatedtherewith for removing foam formation from the liquid under treatment'soas to prevent discoloration of the vnal product vide in a process ofproducing milk sugar, a n ovel` means of obtaining the product fromasupersatu-1 rated heated solution, by means of a chilling step thrownout of solution.

The invention will be best understood from a consideration. vofthefollowing detailed-descripl tion taken inconnection Withtheaccompanying drawings Vforming part of this -speciiicationl with.

tions markno materialdeparture from the salient` features of theinvention asexpressed inthe .ap-

pended claims.

Figure 1 is a diagrammatic lay-out" of the apparatus vemployed.incarrying out the .present procesa` f Figure 2 is a viewillustratingzdiagrammatically the improveddehydrator and skimmerstructure which forms a part `of'theapparatus,'v i Figure 3 isadiagrammatic ysectional view .taken across the end oftheevapora'torfremote Afrom the gas inlet end thereoff `While .thepresent processmay belus'ed for'preparing solid forms :of a `number ;ofliquids-.such as milk, whey, etc., as previously :stated, the :processhas been designed primarily .for the production of milksugar `from wheyand this particular process .will rst beset forthf l 'Stated generally,whey fromcasein' or .cheese making.processes .is run 'into 'a'suitablatank for Vheatingwhere the temperature of,V the same is raisedto approximately" F.y The ywhey is then acidulated, if necessary, toybring its acid content up Vto at least 0.3% andthe temperature e 'isthen raised toapproximately 158.F. `orhigher to effect Vpre'ci'pitatio-nof .albumen and .casein and .the precipitated .substances are` thenremoved by `any suitable process as by flltration or centrifuging. 1 Theprecipitated albuinen isremoved and dried as a separate product. f y

'.The liquor remaining after removal of the al- .bumenthenhas activatedcharcoal added thereto, in an amount applximatingrromlto 2% :of thesugar content of Vthe Whey andkafterLthor- 1 -oughly agitating the.liquid withthe charcoal, va. suitable :alkali such as lime v(calu'moxide), or Vcalcium hydroxide is added to'assist .in precipitation ofthe carbonand othersuspended impuri` ties which arethenltered-outby-anysuitable Atype ofv iilter.v The precipitate is removed land driedfor separate ,disposal as chicken char and food.` r

` The clear and colorlessjltrate remaininga-tter l the foregoing stepslhave been carri'edfout, isI then evaporated `byA spraying thessame`in'a suitable apparatus,hereinafter` more .specifically de-- scribed,`against a current of..heated. waste stack gasesA oriflue .gases orotherinertgases. The wasteilue gases may. be used while carrying'wasteheator,. if necessary, they may be regenerated by. cooling tolremove moisture and reheating and .repassin'g .through .the evaporator.This .evaporatinggprocess:is carried outby repeat'- ledly spraying` theliquid against theowinggases andthe liquidrecovered from each sprayingAis `skimmed to remove foam therefrom and this foam is vreturned' intothe stream. of liquid passing to theysprayer and is respra-yed'with thecooler liquid. The spraying yoperationncauses the liquid Aand poweredand is ready for commerce.

to take up heat from the drying gases and, therefore, the liquidinitiallycoming into the evaporator is at a much lower temperature thanthat which is taken out for respraying and the skimmed oli foam ispreferably returned to the original liquid line so that it will enterand mix with the cooler liquid iiowing to the evaporator.

The claried liquorlis concentrated by. means of these successive stagesof sprays to a desired point close to saturation of dissolved solidsVrat its existing temperature (below boiling)- The concentrated liquid isthen run through a'lter, if necessary, to remove any suspended solidsand from this filter it is carried to a cooler of any suitable typewhere the temperature is reduced.

The reduction of the temperature of the concen- 'uidis'"'teturned to oneof' the spraying stages of the evaporator to be resprayed with the othervliquid coming theeinto. v The removed sugar may then be washed withWater of its own-'or approximatelyofthe same temperature and thewashedsugar is then dried The wash water may be returned with thelastltrate, that is, the ltrate removed after pre-V cipitating the sugarfrom the solution, to the evaporator. a Y

` To set forth morefspecically the operation of the process, referencewill be made-to the accompanying drawings wherein `is shown,particularly in Figure 1, a diagrammatic layout of the several pieces ofapparatus employed and the mannerin which they are coupled together. Theoperation can best be described asA follows;

Two tanks are preferably employed, as indicated by the` numeral I, eachof which has a capacity of one days whey production and these tanks are'preferably constructed with jackets 2, so'that they may be heated byVsteam'or hot gases. These tanks I receive alternately the daysproduction of whey. Each tank has a suitable Ameans at its bottom forremoving sludge, which means is indicated in the drawings by the numeral3 and is connected with a pipe 4 and in addition to the sludge removingmeans, a suitablel skimming means 5 is associated with each tank forremoving from the top of the liquid, the floating precipitated orocculated albu-" men. Y 'I'his material is carried by the skimmertorasuitable chamber 6 into which it is discharged and from which it iscarried through the pipe line 'I to the albumen lter 8. l

After the whey has been introduced into a tank and heated toapproximately 140 F., 'as previouslystated, it is analyzed for its acidcontent and the content of acid raised, if necessary, to approximately0.3% by the addition of more acid, preferably an organic acid, such aslactic', acetic or4 tartaric acids. The temperature is then increased to158 F. or more, or to the boil- -ing point, ii desired'. Thesevariations control in some measure the characteristics of theprecipitated albumen. The albumen, part of the globulin andfibrinarethus preciptated and, the heat being stopped, will rise to thesurface where they are removed byY ld'e skimmer to the lter `8. Thisfilter is provided with a recirculating means consisting of thepump 9and the lines IDLand II so that il? the rst liquor passing through thelter 8 is cloudy, it may be recirculated therethrough until clear andthen returned to the tank I through the line I2.

The albumen cake is removed from the lter and disposed of, as previouslystated, and to the tank I in which the whey is located, there is addedthe activated carbon previously referred to and the precipitation. ofthe carbon, by means of the lime or other suitable alkali, is effectedin this tank. 4The lime is added to the extentv necessary to produce aheavy and rapidly precipitating floc which is allowed to settle to thebottom and is removed through the desludging apparatus 3 to thecharcoal-and lime iilter structure I3. Asrin the case of theA albumen,recirculation of the material entering the filter I 3,- is carried outuntil the ltrate is clear and after this result has been obtained, theclear.

filtrate is returned by the line I4 to the particular tank which is inuse.

The now clear colorless liquid is passed from the tank IY by means ofthe pipe line I5, to the iirst stage of the drier or evaporator.

The evaporator is indicated generally'by., the numeral I6 and comprisesan elongated chamber I'l having the inlet I8 atV one end through whichthe hot flue gases or otherinert .gases are introduced for passagelongitudinally through the chamber. `A djacent the end of the evaporatorchamber remote from the inlet I8,the pipe line I5 enters the evaporatorstructure, as illustrated in Figure 1. Also, adjacent this end of theevaporator structure is a spray unit which is generally designated by.the numeral I9.

',Ihe bottom of the evaporator is in the form y of a long trough or sump20 which is transversely" divided at spaced intervals by partitions 2Iso as to f orm a series of individual receptacles 22 and extendingtransversely of the evaporator kstructure `at the end of the longtrough-like bottom portion 20 remote from the inletVV I8 is afoamreceiving sump 23. This sump has leading from the lower part thereofa pipe line 24 which is employed to return foam which-has been collectedin the sump 23 from the top of the' liquid in the receptacles 22, backto the pipe lines leading to the receptacles I from the lines I2 and I4.It willthus be seen that the foam Whichygathers in thesump 23 will be.re-

turned to the receptacle froml which the. liquid skim the surface of theliquid in the receptacles Y22 and pass over the top edges of thepartitions 2l so that foam will be removed from the top of thev liquidinthereceptacles and carried across the inner edge of the sump 23 whichextends transversely of the evaporator." Y

Each of the liquidreceptacles 22 has a sprayer unit associatedVtherewith, thefsprayer units, in addition to the unit I9 previouslyAreferred to, being indicated Aby the numeralv 28. Each of these unitsI9. and 28 is connected with the outlet side of a pump 2'I which hasitsinlet connected directly with the receptacle adjacent which the sprayerunit islocated. The outlets vof the sprayer units arepreferablyvdirec'ted laterally `inzthe evaporator structure so that theclarified whey liquor will be discharged generally toward" theY flow iscounter l,tothe gases, (i. e.) the least concentrated liquor, enteringthrough thenozzles.

ofthe spraying units i8, 'encounters the coldest and most saturated gasand thus, stage bystage, passes through successive sprays; becoming'moreand more concentrated fand encounteringjless' Y and less saturated gasof `higher and higher tem--V perature.

This order of spraying fis used becausethe `aqueous vapor tensiondifferential between V74the drying medium and the solution is reduced byconcentration;V that Vis; a concentrated "solutionV holds its Water morevreadily thana diluteand the differential of Laqueous vapor tension in-Y creases with the temperature differentialof the drying medium andsolution, the drying medium being higherV than 'the solution, of course,permitting greaterabsorption of water from theV solution by the dryingagent. Also, unless these .differentials are so taken advantageof,itwould Vbe nearly impossible to achieve the desired degree ofconcentration." Y e The spray outlets of-'the units I S and 28, aspreviously stated, project the whey atan angle to theA longitudinal axisof the vdryer fand onto fthe walls of Ythe same,as well as dropping lthewhey directly into the pan'below.Av The last stage of sprays `isdirected with'theow'of vgasesxfor the purpose of preventing depositionof--the highly concentrated whey in too hot a zone with vthe centratedliquor. y

It will thus be seen'that the circulation ofthe whey liquid in theevaporator is out of one pan through the pump and spray unit directlyassociated therewith and back tothe same pan and the iiow from this panis over the dividing wall 2| into the next pan or receptacle.

Leading from the last receptacle 22 which is the one nearest the inletI8, is a pipe 28 through which the concentrated liquid passes to one ofthe two filter units 29' which areconnected in parallel.' as shown andcontrolled'- by suitable valves so that a selected one of the units maybe used. 'Ihe liquid concentration proceeds in the evaporator preferablyuntil it Vreaches at least 65% of saturation of sugar at the temperatureo1 the solution and the liquor at this concentrationV is then withdrawnby means of the pipe line 28'r and passes while hot or as near aspossible to the temperature of Withdrawal-through the lter 29', thusremoving suspended impurities.. The liquid, after nal :tiltrationis thencarried to a precipitator 29 where it is subjected to chilling orcooling so-that the temperature'is substantially reduced as, forexample, from a high of around 150 F. to approximately 72 F.Thischilling action eiects the precipitation of the tratedslution andtheprecipitate is then passed to a washerll andthe remaining or supernatantY y liquid maybe returned to the evaporator'for Y resprayingwith-theother liquid passing therethrough; Thesugar is washed with water havingatl-temperature of'` approximately the same `degree as the sugar and thewashi water is also'returned Y to theevaporator as by the line 3|, sothat anysugar'v dissolvedv therein may be r reobtained with thenextvpeci'pitaton.

From thev foregoing, it will be readily apparentV that with the presentprocess, theproduction of milkv sugar can be made continuous' and thatthe possibility of charring ordiscoloring the same is remote 'because oftheconstant removal of the foam fromthe evaporator. f Where th-processis to be used for the production of dried products from whole whey,milk.

skiminilk, butter milk orany liquid or fluid containing solids in'suspensionthe solution or suspension A.to be dehydrated is4 introducedto -thel first stagev of the spraydrier and passes, as before described,from st'age'fv to stage. The foam producedfisfremoved :byl theVskimmerand reliqueed before introduction.

`When theliquor has reacheda'concentration of 2o` to emisoras 1in itscount@'r-flowfto the hot gases, it 4is atomized` byf'a mechanicalsprayin its lastfstage anddried to `completion,"beingre-f,

moved either asit falls onto a suitab1efmoving receiver or'by meansof'sucti'on or 'any other 'oneof-thewell known methods of removing ma'-yterials frorrrgdehydrating apparatus.

. The evaporatorstructure at the rear end over thefoarn` receivingsump23 is of Astandard construction and has, therefore, beenV onlydiagrammatically illustrated'.V Such standard construction .comprises aplurality of horizontally disposed corrugated plates 32 arranged inverticallyspaced relation so`that the 'moisture laden-heated air orgases which` have passed Vthroughthe evaporator=wi1l be required tofollowa-zig-zag course beforey escaping through thefopen rear endthereof4 and thus, throughxcont'act with these plates,`

deposit theentrainedmoisture on the plates from r where it mai7 drainback into the underlying sump consequent risk of baking and charringthe` coni233" The gasesafter `passing out-,bf the real-1V end cof. theVevaporatormay bedischarged into the atmosphere or maybe mixed with'other gases -of VVhigh temperature-:to reduce the? temperature of tranceopening` I8 Yfor reuse.v

I claim:-

1.\The continuous process for the'production of milk sugar, `whichcomprises heat .treating whey having an acid content'of at least 0.3 ata temperature ranging between 158 F. and its boilf ing point to effetprecipitation of` albumen and caseinbut not permitting the whey to boil,re-

, moving the precipitated albumen and casein, adding activatedcharcoalto the supernatant liquid, precipitating the` charcoal with lime'toclarify the liquid, evaporating the liquid remaining after relmoval ofthe charcoal by repeatedly spraying the 1 same against a current of avheated Vdrying fluid until a desired Vconcentration of the liquid isobtained, chillingy the concentrated liquid to effect precipitationof'milk sugar therefrom, and recovering the precipitated sugar anddrying the same. iVV

2. The continuous process for the production of milk sugar fromwhey,which comprises acidulating the whey `by additionl of one of thegroupconsisting ot'lactic, acetic and tartaric acids if 75 necessary tobrithe acid content to 0.3%.'heat treating the acidulated whey at atemperature sufficient to precipitate the albumen. and casein andwithout permitting the Whey to boil, removing the precipitate', addingactivated charcoal to the supernatant liquid in the proportion of fromone to two percent of the same to the sugarcantent,` effectingflocculation of the charcoaland clarification of thefliquid byvprecipitatingwith one of the group consisting ofcalcium oxide and`calcium hydroxide'removing the precipitated floc,

concentrating the clarified liquid by repeatedly spraying the sameagainst a current of'aheated drying and inert gas until a desiredconcentration is obtained, precipitatingmilk sugarfrom the concentratedliquid by reducing the temperature thereof, and finally recovering Vanddrying the l precipitated sugar.

3. ,The continuous process for the production of milk sugar, whichAcomprises the progressive steps of raising the acid content of whey toapproproximately. .3% by addition of one of the group consistingoflactic, acetic and tartaric.acidsraising the temperature of theacidified whey to not high.-

er than the boiling point to precipitate albumens by eiectingcoagulation of, the same, clarifying the supernatant liquid by use ofactivated charcoal and lime in the order named, concentrating theclariiied liquid by contacting the same with c. heated inert gasandsimultaneously raising the crating the clarified liquid by repeatedspraying Y of thesame against'a current of heated inert gas `toV reducethe liquid to a desired concentration, precipitating the milk; sugarfromthe concentrated'liquid by chilling the liquid, and removing anddryingthe precipitate.

- 5. The continuous processvfor the production of milk sugar, whichcomprises raising the acid content of whey from casein orcheesemanufactories to approximately .3% by the addition thereto of anYorganic` acid selected from the group consist'- ing of lactic, aceticand tartaric acids, then increasing the Atemperature of the acidulatedWhey to at least 158 F. to effect precipitation of albumen, globulin andbrin, removing the precipitate, then adding activated carbon to thesuper: natant liquid,`then precipitating the carbon by the addition tothe liquid of an alkali selected 'from the group consisting of calciumoxide and calcium hydroxide, removing the, precipitate, and

Vfinally concentrating the liquid to effect the extractiontherefrom bycrystallization ofthe milk sugar.

6. vThe continuous process ior the production of milk sugar, whichcomprises heating Whey from vcaseinor cheese manufactories to latemperature of approximatelyfli? then raising the acid contentof theheated whey to approximately .3% by adding oneof the group consisting oflactic, aceticv and tartaric acids, then further raisingV thetemperature of the acidulated liquid to at least 158 F. :and not higherthahthe boiling point thereof by which the precipitation of albumen,globulin and fibrin is effected, removing the pre-y cipitate, thenadding activated carbon to the supernatant liquid, then adding Ycalciumoxide in suiiicient quantityto Aeffect precipitation of the carbon,removing the precipitated carbon and calcium, and iinallyVconcentratngthe liquidto effect crystallization of the milki sugar andextracting the same. Y

7. A continuous process for the production of milk sugar, whichcomprises increasingv the acidV content of whey to approximately.3%bythe .addition of tartarlcacid thereto, then heating the aoidulatedwhey to at least 158 F. whereby precipitation of albumen is effected,removing the precipitated albumen, then mixing lwith the supernatantliquid activated carbon in an amount approximating from 1% to 2% of thesugar content of the wheyandthoroughly agitating the carbon containingliquid to eiect thorough distribution of the carbon therethrough, thenadding calcium hydroxide to the carbon containing liquid toeffect theprecipitation of the carbonand residual alburnen, separatingtheprecipitate from the liquid, and finally concentrating the liquid toeiect extraction of the contained milk sugar by crystallization. AUGUSTEDE LISLE.

